Drugs For Treating Asthma

1. Drugs For Treating Asthma Chapter 9

2. Sympathomimetic Agents • Noninfectious respiratory diseases are divided into two groups • Asthma is characterized by reversible airway obstruction • Chronic obstructive pulmonary disease (COPD) is characterized by irreversible airway obstruction • COPD is further divided into emphysema and chronic bronchitis

3. Sympathomimetic Agents - Continued • Beta-Adrenergic Agonists • Nonselective adrenergic agonist drugs stimulate beta receptors in the lungs and heart and alpha receptors in the heart • Epinephrine and isoproterenol are nonselective adrenergic agonists • Today, short- and long-acting β2-agonists are used to treat asthma and COPD • Β2-Agonists stimulate receptors in the lungs. • Stimulation of these receptors produces bronchodilation • Adverse effects include nervousness, tachycardia, and insomnia

4. Respiratory Drugs • Beta-Adrenergic Agonists • Short-Acting β2-Agonists • These drugs are used to treat acute asthma attacks. • They are usually administered via metered dose inhalers • They are available in tablet and liquid dose forms. • Short-acting β2-agonists are often used as prophylaxis prior to exercise or another known precipitating event

5. Long-Acting β2-Agonists • These agonists have a delayed onset of action and a longer duration of action • Onset of action is within 10-20 minutes and the duration of action of 12 hours. • These drugs are used as maintenance therapy in the treatment of asthma and COPD

6. Metered Dose Inhalers (MDI) • These devices deliver the medication directly to the bronchioles • The total dose is kept low and side effects should be minimal • The inhaled dose can be accurately measured • Onset of action is rapid and predictable • They are compact, portable, and sterile • They can be difficult to use • Spacers are available which makes the inhaler easier to use • Adverse effects with MDI use include dry mouth

7. Corticosteroids • Steroids reduce the inflammation associated with airway obstruction • They also inhibit the release of inflammatory substances • Steroids are available as MDIs and oral and liquid dose forms • The MDI has become the most common dose form used in treating asthma and COPD

8. Corticosteroids - Continued • Corticosteroids significantly improve pulmonary function with a decrease in wheezing, tightness, and cough • These drugs are not used for acute attacks. • Chronic oral prednisone use is reserved for patients with severe asthma • Adverse effects are dependent upon dose form, frequency of intake, total dose, and any preexisting conditions

9. Corticosteroids - Continued • Prolonged systemic use can lead to adrenal suppression, poor wound healing, and immunosuppression • MDI use can lead to oral candidiasis. • Patients using inhaled steroids should be instructed to brush, floss, rinse, and spit, after each use

10. Leukotriene-Pathway Inhibitors • These drugs work by either preventing the synthesis of leukotrienes or by blocking leukotriene receptors • Leukotriene release produces bronchoconstriction, increased mucus secretion, mucosal edema, and increased bronchial hyperreactivity • These drugs are used to treat asthma and allergic rhinitis • Adverse reactions include irritation of the stomach mucosa, headache, and altered liver function tests

11. Cromolyn • Cromolyn inhibits mast cell degranulation. • It is used for the prophylaxis of asthma • It can be used in patients with chronic asthma or taken before exercise-induced asthma • Adverse effects include cough, dry mouth, nausea, and headache • It is available as a nebulizer or in a spinhaler dose form

12. Methylxanthines • Theophylline is the main drug in this category • It is a bronchodilator with a narrow therapeutic window • It is used to treat severe asthma and the bronchospasm associated with COPD • Side effects include CNS stimulation, cardiac stimulation, and GI upset

13. Anticholinergic Drugs • Ipratropium bromide is an inhaled anticholinergic drug that is used to treat asthma and COPD • Its anticholinergic effects produce a bronchodilating effect in the lungs • Side effects include dry mouth. The patient should rinse after each inhaler use to minimize dry mouth

14. Role of the Athletic Trainer • Educate the patient in regards to: • The type of medication they are taking • Specific effects in regard to athletic performance • Understand proper inhalation technique • Take action to adjust specific drug through consultation if necessary • Keep medication readily available • Monitor the patient during exercise • Know the medications the athletes are using